<template>
  <view>
    <!-- 使用自定义的搜索组件 -->
    <my-search @click="gotoSearch"></my-search>
    <view class="scroll-view-container">
      <!--  左侧滑动区域  -->
        <scroll-view class="left-scroll-view" scroll-y="true" :style="{height: wh +'px'}">
          <block v-for="(item,index) in cateList" :key="index">
            <view :class="['left-scroll-view-item',index===active?'active':'']" @click="activeChanged(index)">{{item.cat_name}}</view>
          </block>
        </scroll-view>
      <!-- 右侧滑动区域-->
        <scroll-view scroll-y="true" :style="{height: wh+'px'}" :scroll-top="scrollTop">
          <view class="cate-lv2" v-for="(item2,i2) in cateLevel2" :key="i2">
            <!-- 二级分类的标题 -->
            <view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
            <!-- 当前二级分类下的三级分类列表 -->
            <view class="cate-lv3-list">
              <!-- 三级分类的item项 -->
              <view class="cate-lv3-item" 
              v-for="(item3,i3) in item2.children" :key="i3"
              @click="gotoGoodsList(item3)"
              >
                <!-- 三级分类的图片 -->
                <image :src="item3.cat_icon"></image>
                <!-- 三级分类的文本 -->
                <text>{{item3.cat_name}}</text>
              </view>
            </view>
          </view>
        </scroll-view>
    </view>
  </view>
</template>

<script>
  import badgeMix from '@/mixins/tabbar-badge.js'
  export default {
    mixins:[badgeMix],
    data() {
      return {
        // 当前设备可用的高度
        wh:0,
        cateList:[],
        active:0,
        // 二级分类的列表
        cateLevel2:[],
        scrollTop:0
      };
    },
    onLoad(){
      const sysInfo=uni.getSystemInfoSync()
      this.wh=sysInfo.windowHeight-50
      //获取分类数据
      this.getCateList()
    },
    methods:{
      async getCateList(){
       const {data:res}= await uni.$http.get('/api/public/v1/categories')
       if(res.meta.status!==200)return uni.$showMsg()
       this.cateList=res.message
       // 为二级分类赋值
       this.cateLevel2 = res.message[0].children
      },
      activeChanged(index){
        this.active=index
        // 重新为二级分类赋值
        this.cateLevel2=this.cateList[index].children
        
        this.scrollTop = this.scrollTop===0 ? 1 :0
      },
      // 跳转到商品列表页面
      gotoGoodsList(item){
        uni.navigateTo({
          url:'/subpkg/goods_list/goods_list?cid='+item.cat_id
        })
      },
      gotoSearch(){
        uni.navigateTo({
          url:'/subpkg/search/search'
        })
      }
    }
  }
</script>

<style lang="scss">
.scroll-view-container {
  display: flex;
  .left-scroll-view {
    width: 120px;
    .left-scroll-view-item {
      background-color: #f7f7f7;
      line-height: 60px;
      text-align: center;
      font-size: 12px;
      &.active {
        background-color: #fff;
        position: relative;
        &::before {
                  content: ' ';
                  display: block;
                  width: 3px;
                  height: 30px;
                  background-color: #c00000;
                  position: absolute;
                  left: 0;
                  top: 50%;
                  transform: translateY(-50%);
        }
      }
    }
  }
}
.cate-lv2-title {
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  padding: 15px 0;
}
.cate-lv3-list {
  display: flex;
  flex-wrap: wrap;
  .cate-lv3-item {
    width: 33.3%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    margin-bottom: 10px;
    image {
      height: 60px;
      width: 60px;
    }
    text {
      font-size: 12px
    }
  }
}
</style>
